The present invention relates to a gate mechanism for directing a shingled stream of articles, such as books, newspapers, or signatures, in one of a plurality of paths.
Typically, gate mechanisms are interposed between article-handling mechanisms which operate in sequence on a shingled stream of articles, such as between a printing press and collator or between a binder and stacker. Such gate mechanisms normally direct articles in a primary path between the article-handling mechanisms. However, in the event that the downstream article-handling mechanism is overloaded or malfunctions, the gate mechanism operates to direct the articles in a secondary path which may be, for example, to an overflow area or to another downstream article-handling mechanism. As a result, the upstream article-handling mechanism can keep operating, even though a downstream article-handling mechanism is inoperative. Normally, the gate mechanism re-establishes the shingled stream flow in the primary path to the downstream article-handling mechanism after the overload or malfunction has been corrected.
One known gate mechanism is shown in U.S. Pat. No. 4,034,974. This patent discloses a gate which moves to direct a shingled stream of articles in one of two different paths. In the system disclosed in U.S. Pat. No. 4,034,974, a gapmaker provides a gap in the shingled stream. The gate is moved when the gap is adjacent the gate. Thus, the gate does not disturb any of the articles in the shingled stream. The gate mechanisms shown in other patents, such as U.S. Pat. No. 2,392,032, direct articles which are spaced apart rather than in a shingled stream. In such mechanisms, the gate is normally moved during the time interval when the gate is adjacent a space between the articles. Otherwise, the articles would be disturbed by movement of the gate.